1. Field of the Invention: This invention is in the field of interlocking structures for enclosing the top of a trailer vehicle.
2. Description of the Prior Art: Numerous types of tarpaulin or canvas covers are known in the prior art for attaching to and covering the upper open end of trailer vehicle bodies. Such a prior art device is disclosed in U.S. Pat. No. 3,511,408 issued to E. Hughes. Canvas covers provide many disadvantages. A main disadvantage is the installation and removal of the canvas cover. Generally, two men are required to remove a canvas cover or to install the canvas cover on the vehicle. During winter, the ropes used to secure the canvas cover become frozen requiring ice removal from the ropes as well as the canvas cover. Canvas covers are quite susceptible to cuts and tears and water penetration allowing for possible damage to the freight. Likewise, it is very easy for thieves to cut the canvas cover in order to remove the freight from the vehicle. Canvas covers also have a relatively short life due to tree limbs, ice, vandals and low overhangs damaging the canvas. It is therefore desirable to provide a different and better means for covering the open top end of a truck or trailer vehicle.
A partial solution to the above problems is to mount a rigid cover to the truck. Such a cover is disclosed in U.S. Pat. No. 3,180,674 issued to C. C. Pounds. The Pounds cover is designed for permanent installation on a pick-up truck and as such is not easily adaptable to long flat-bed trucks such as semi-trailers. Another type of permanent installation for a pick-up truck is disclosed in U.S. Pat. No. 3,489,456 issued to R. A. Klanke. A slightly different version wherein the cover is slidably mounted to the pick-up truck is disclosed in the U.S. Pat. No. 3,765,967 issued to William J. Ahrens. In a related industry, covers for gondola cars are disclosed in U.S. Pat. No. 2,674,208 issued to W. M. Keller et al. A cover assembly having a plurality of panels telescopically connected together for mounting to the rear portion of a truck is disclosed in the U.S. Pat. No. 3,342,523 issued to C. J. Lutgen.
Disclosed herein is a new and improved panel assembly for enclosing the open top end of a trailer vehicle. The panels are relatively heavy and large requiring removal of the covers of the panels from the trailer vehicle by a crane preventing ready removal of the panels by thieves. The panels are secured to the trailer with metal hinges and cables decreasing the possibility of accidental disengagement of the panels relative to the trailer during transit of the trailer. Theh panels are produced from fiber glass and will have a longer life as compared to tarpaulin or canvas covers. The panels disclosed herein may be produced from fiber glass eliminating the maintenance normally required with canvas covers. The fiber glass panels are relatively more expensive initially as compared to canvas covers; however, by eliminating the maintenance expenses the subject panels will be considerably less expensive over a period of time.
A practical disadvantage relative to canvas coverings is the amount of time required to remove or install the covering on the trailer. When a canvas covered trailer is empty, often the trailer is not covered due to the difficulty involved. The canvas cover typically is thrown in the trailer on the floor or dropped in a storage area open to the rain and snow. The floor of the trailer will then become damaged from the elements since the trailer is not covered by the canvas cover. The cover disclosed herein must be removed by a crane and likewise must be replaced with a crane. Thus, after the trailer is unloaded the cover is placed back on the trailer in order to free the crane for use in other areas. Since the subject cover is composed of a plurality of individual panels, not all the panels must be removed for loading and unloading. The trailer may only be partially unloaded without requiring complete removal of the cover.